Alkoxylation process catalyzed by rare earth and phosphorus-containing xerogels

ABSTRACT

Alkylene oxide adducts of organic compounds having active hydrogen atoms are prepared by a process which comprises contacting and reacting an alkylene oxide reactant comprising one or more vicinal alkylene oxides with an active hydrogen containing reactant comprising one or more compounds having active hydrogen atoms in the presence of a catalytically effective amount of a xerogel comprising one or more compounds comprising a rare earth element and phorphorus. The product alkoxylates are known to be useful, for instance, as nonionic surfactants, wetting and emulsifying agents, solvents, and chemical intermediates.

FIELD OF THE INVENTION

This invention relates to an alkoxylation process in which alkyleneoxides are reacted with compounds having active hydrogen atoms in thepresence of a catalyst comprising a xerogel comprising one or morecompounds of a rare earth element and phosphorus. In particularlypreferred embodiments, the invention relates to processes for thepreparation of alkoxylate products useful as nonionic surfactants.

BACKGROUND OF THE INVENTION

A large variety of products useful, for instance, as nonionicsurfactants, wetting and emulsifying agents, solvents, and chemicalintermediates, are prepared by the addition reaction (alkoxylationreaction) of alkylene oxides (epoxides) with organic compounds havingone or more active hydrogen atoms. For example, particular mention maybe made of the alkanol ethoxylates and alkyl-substituted phenolethoxylates prepared by the reaction of ethylene oxide with aliphaticalcohols or substituted phenols of about 6 to 30 carbon atoms. Suchethoxylates, and to a lesser extent corresponding propoxylates andcompounds containing mixed oxyethylene and oxypropylene groups, arewidely employed as nonionic detergent components of commercial cleaningformulations for use in industry and in the home. As another example,the addition reaction of propylene oxide with polyols providesintermediates for the preparation of polyurethane products.

An illustration of the preparation of an alkanol ethoxylate (representedby formula III below) by addition of a number (n) of ethylene oxidemolecules (formula II) to a single alkanol molecule (formula I) ispresented by the equation ##STR1##

The addition of alkylene oxides to alcohols and other active hydrogencontaining compounds is known to be desirably promoted by a catalystwhich is in conventional practice either basic or acidic in character.Recognized in the art as suitable basic catalysts are the basiccompounds of the alkali metals of Group I of the Periodic Table, e.g.,sodium, potassium, rubidium, and cesium, and the basic salts of certainof the alkaline earth metals of Group II of the Periodic Table, e.g.,calcium, strontium, barium and in some cases magnesium. Conventionalacidic alkoxylation catalysts include, broadly, Lewis acid orFriedel-Crafts catalysts. Specific examples of these acid catalysts arethe fluorides, chlorides, and bromides of boron, antimony, tungsten,iron, nickel, zinc, tin, aluminum, titanium and molybdenum. The use ofcomplexes of such halides with, for example, alcohols, ethers,carboxylic acids, and amines has also been reported. Still otherexamples of known acidic alkoxylation catalysts are sulfuric andphosphoric acids; perchloric acid and the perchlorates of magnesium,calcium, manganese, nickel and zinc; certain metal oxalates, sulfates,phosphates, carboxylates and acetates; alkali metal fluoroborates; zinctitanate, and certain metal salts of benzene sulfonic acid.

Other art on the subject of alkoxylation includes U.S. Pat. No.4,727,199 which describes a process for reacting a liquid or solidalkylene oxide with a liquid or gaseous active hydrogen compound in thepresence of a catalytic amount of an anion-bound metal oxideheterogenous catalyst, wherein the anion is SO₄, BF₄, CO₃, BO₃, PO₄,SeO₄, MoO₄, B₄ O₇ or PF₆ and the metal oxide is an oxide of zirconium,nickel, aluminum, tin, calcium, magnesium, iron, titanium, thorium,hafnium, or rubidium. Still other prior art describes the use ofzeolitic materials as alkoxylation catalysts, while European patentapplication 0250168 and other art cited therein disclose lamellar claycatalysts.

Alkylene oxide addition reactions are known to produce a product mixtureof various alkoxylate molecules having different numbers of alkyleneoxide adducts (oxyalkylene adducts), e.g., having different values forthe adduct number n in formula III above. The adduct number is a factorwhich in many respects controls the properties of the alkoxylatemolecule, and efforts are made to tailor the average adduct number of aproduct and/or the distribution of adduct numbers within a product tothe product's intended service. In certain preferred embodiments, thepresent invention provides a process characterized by enhancedselectivity for the preparation of alkoxylate mixtures in which arelatively large proportion of the alkoxylate molecules have a number(n) of alkylene oxide adducts that is within a relatively narrow rangeof values.

It is known in the art that alcohol alkoxylate products having a narrowrange alkylene oxide adduct distribution are preferred for use incertain detergent formulations (Great Britain Patent No. 1,462,134,Derwent Publications Research Disclosure number 194,010). Narrow-rangealcohol alkoxylates are also known to be particularly valuable aschemical intermediates in the synthesis of certain carboxyalkylatedalkyl polyethers (U.S. Pat. No. 4,098,818) and of certain alkyl ethersulfates (Great Britain Patent No. 1,553,561). Conventional commercialalkoxylate preparation, which has in large part been limited to the useof basic catalysts. particularly the metals sodium and potassium andtheir oxides and hydroxides, yields only a relatively broad distributionrange product. Conventional acid-catalyzed alkoxylation reactions havelong been known to produce a more narrow range product than thatobtained with the alkali metal catalysts. However, acid catalysts havesubstantial disadvantages in several other respects. For instance, theacids are often unstable with limited life and effectiveness ascatalysts in the alkoxylation mixture. Both the acid catalyststhemselves and their decomposition products catalyze side reactionsproducing relatively large amounts of polyalkylene glycols, and alsoreact directly with the components of the alkoxylation mixture to yieldundesirable, and often unacceptable, by-products such as organicderivatives of the acids.

Also of substantial importance in alkoxylation processes is the abilityof the process to minimize the quantity of unreacted (or residual)active hydrogen reactant remaining in the final product. A high level ofresidual reactant either represents a loss of valuable reactant, orrequires that further processing of the product be carried out torecover the reactant. Moreover, the presence of the unreacted materialis often a disadvantage from the standpoint of product quality andenvironmental concerns. For instance, residual alkanol in a detergentalcohol ethoxylate product contributes to volatile organic emissionsduring spray drying of detergent formulations.

It has recently been reported in the art that, in addition toconventional acidic catalysts, a number of other substances have beenfound to function as catalysts or in co-catalyst combinations which arecapable of producing relatively narrow distributions for the oxyalkyleneadducts of higher alkanols and other active hydrogen containingcompounds. For instance, it has recently been disclosed (U.S. Pat. Nos.4,306,093 and and 4,239,917, and published European Patent ApplicationNos. 0026544, 0026546, 0026547) that certain compounds of barium,strontium, and calcium promote narrow-range alkoxylation products. U.S.Pat. Nos. 4,210,764 and 4,223,164 describe the use of cresylic acids topromote alkoxylation catalyzed by barium and strontium compounds. U.S.Pat. No. 4,302,613 discloses that a more peaked reaction product can beobtained by combining barium and strontium alkoxylation catalysts withco-catalysts such as calcium oxide, calcium carbide, calcium hydroxide,magnesium metal, magnesium hydroxide, zinc oxide and aluminum metal.U.S. Pat. No. 4,453,023 describes a process for preparing alkoxylateshaving a narrower molecular weight distribution which employs a catalystcomprising a barium compound and a promoter selected from the classconsisting of superphosphoric acid, phosphoric acid, diphosphoric acid,triphosphoric acid, phosphorous acid, dihydrogen phosphate compounds,oxides of phosphorus, carbon dioxide, and oxalic acid. U.S. Pat. No.4,453,022 describes a similar process wherein the catalyst comprises acalcium or strontium compound and a promoter selected from the classconsisting of superphosphoric acid, phosphoric acid, diphosphoric acid,triphosphoric acid, phosphorous acid. dihydrogen phosphate compounds,oxides of phosphorus, sulfuric acid, bisulfate compounds, carbonic acid,bicarbonate compounds, carbon dioxide, oxalic acid and oxalic acidsalts, sulfur trioxide, sulfur dioxide, and sulfurous acid. PublishedPCT application WO 85/00365 discloses other activated calcium containingalkoxylation catalysts capable of producing narrow range alkoxylationproducts. U.S. Pat. No. 4,375,564 reports that a narrow range productresults from alkoxylation reactions catalyzed by a magnesium compound incombination with a compound of one of the elements aluminum, boron,zinc, titanium, silicon, molybdenum, vanadium, gallium, germanium,yttrium, zirconium, niobium, cadmium, indium, tin, antimony, tungsten,hafnium, tantalum, thallium, lead and bismuth. U.S. Pat. No. 4,483,941discloses catalysts for alkoxylation reactions which comprise either BF₃or SiF₄ in combination with an alkyl or alkoxide compound of aluminum,gallium, indium, thallium, titanium, zirconium, and hafnium. U.S. Pat.No. 4,456,697 describes an alkoxylation catalyst which comprises amixture of HF and one or more metal alkoxides. Japanese patentspecification 52051307 to Tokuyama Soda KK discloses the selectivepreparation of mono- rather than di- or tri-alkylene glycol esters fromalkylene oxide and alcohol using solid acid catalysts such as silica,alumina, titania, vanadium pentoxide, antimony pentoxide, titanylsulfate, tungstic acid, phosphotungstic acid, and silver perchlorite.

Recently issued U.S. Pat. No. 4,721,816 claims a process for preparingnarrow range distribution alkoxylates, wherein the catalyst is acombination of one or more sulfur-containing acids with one or morealuminum alcoholate or phenolate compounds. U.S. Pat. No. 4,721,817claims a similar process wherein the combination contains one or morephosphorus-containing acids.

U.S. Pat. Nos. 4,665,236 and 4,689,435 describe a process for thealkoxylation of active hydrogen reactants using certain bimetallic oxocatalysts. The catalysts described in U.S. Pat. No. 4,665,236 includecompounds in which one of the metal species in the bimetallic moleculeis lanthanum, and European application 0250168 discloses lamellar claycatalysts which have been ion exchanged with lanthanum and other rareearth elements.

The alkoxylation catalysts in the references discussed above areprepared by conventional methods such as simple chemical reactions,i.e., acid-base or metathesis reactions, or methods known in the artsuch as ion exchange.

It has now been found that hydrogel-derived xerogels comprising one ormore compounds comprising a rare earth element and phosphorus areeffective catalysts for the addition reaction of alkylene oxides withorganic compounds having active hydrogen atoms. It has further beenfound that, in certain preferred embodiments, an alkoxylation reactioncatalyzed by a xerogel comprising one or more compounds comprising arare earth element and phosphorus provides an alkoxylate product,particularly an alkanol ethoxylate product, of exceptionallynarrow-range alkylene oxide adduct distribution.

SUMMARY OF THE INVENTION

The present invention is particularly directed to a process for thepreparation of alkoxylates of active hydrogen containing organiccompounds which comprises contacting an alkylene oxide reactantcomprising one or more vicinal alkylene oxides with an active hydrogenreactant comprising one or more organic compounds (e.g., alcohols,phenols, thiols, amines, polyols, carboxylic acids, etc.) having one ormore active hydrogen atoms, in the presence of a catalytically effectiveamount of a xerogel comprising one or more compounds comprising a rareearth element and phosphorus.

As used herein, the term "rare earth" elements are those elements ofatomic numbers 57 through 71. The terms "rare earth element" and"lanthanide" are used interchangeably in the present specification.

As used herein, the term "xerogel" refers to the product obtained bydrying hydrogels whereby the structure is for the most part irreversiblyset. While xerogels may contain a residuum of water, i.e., as much as75% by weight, they are usually encountered as spray dried powderscontaining 65-99% solids and are considered to be rigid solids. As usedherein, the term "hydrogel" refers to gels, precipitated gels, hydrousoxide precipitates, or combinations thereof in an undried state. Wateris a major component of these materials as formed, comprising 80% to 95%of their weight. The water is held within the pores or interstices ofthe semi-rigid hydrogel.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention centers upon discoveries associated with the usein an alkoxylation process of a certain class of catalysts. Apart fromthe use of such catalysts, the process of the invention is, as a generalrule, suitably conducted using such reactants and practicing under suchprocessing procedures and reaction conditions as are well known to theart for alkoxylation reactions. Certain preferences may, however, beexpressed for particular reactants, procedures and conditions.

Thus, for instance, the invention is preferably applied to processesutilizing an alkylene oxide (epoxide) reactant which comprises one ormore vicinal alkylene oxides, particularly the lower alkylene oxides andmore particularly those in the C₂ to C₄ range. In general, the alkyleneoxides are represented by the formula ##STR2## wherein each of the R¹,R², R³ and R⁴ moieties is individually selected from the groupconsisting of hydrogen and alkyl moieties. Reactants which compriseethylene oxide, propylene oxide, or mixtures of ethylene oxide andpropylene oxide are more preferred, particularly those which consistessentially of ethylene oxide and propylene oxide. Alkylene oxidereactants consisting essentially of ethylene oxide are considered mostpreferred from the standpoint of commercial opportunities for thepractice of alkoxylation processes, and also from the standpoint of thepreparation of products having narrow-range ethylene oxide adductdistributions.

Likewise, the active hydrogen reactants suitably utilized in the processof the invention include those known in the art for reaction withalkylene oxides and conversion to alkoxylate products. Suitable classesof active hydrogen reactants include (but are not necessarily limitedto) alcohols, phenols, thiols (mercaptans), amines, polyols, carboxylicacids, and mixtures thereof. Preference generally exists for use ofhydroxyl-containing reactants. More preferably, the active hydrogencontaining reactant consists essentially of one or more active hydrogencontaining compounds selected from the group consisting of alkanols,alkyl polyols and phenols (including alkyl-substituted phenols).

Among the suitable carboxylic acids, particular mention may be made ofthe mono- and dicarboxylic acids, both aliphatic (saturated andunsaturated) and aromatic. Specific examples include acetic acid,propionic acid, butyric acid, valeric acid, caproic acid, lauric acid,myristic acid, palmitic acid, stearic acid, oleic acid, rosin acids,tall oil acids, terephthalic acid, benzoic acid, phenylacetic acid,toluic acid, acrylic acid, methacrylic acid, crotonic acid, maleic acid,and the like.

Among the suitable amines, particular mention may be made of primary,secondary and tertiary alkylamines and of alkylamines containing bothamino and hydroxyl groups, e.g., N,N-di(n-butyl)-ethanolamine andtripropanolamine.

Among the suitable thiols, particular mention may be made of primary,secondary and tertiary alkane thiols having from 1 to about 30 carbonatoms, particularly those having from about 8 to 20 carbon atoms.Specific examples of suitable tertiary thiols are those having a highlybranched carbon chain which are derived via hydrosulfurization of theproducts of the oligomerization of lower olefins, particularly thedimers, trimers, and tetramers and pentamers of propylene and thebutylenes. Secondary thiols are exemplified by the lower alkane thiols,such as 2-propanethiol, 2-butanethiol, and 3-pentanethiols, as well asby the products of the hydrosulfurization of the substantially linearoligomers of ethylene as are produced by the Oxo process. Representativebut not limiting examples of thiols derived from ethylene oligomersinclude the linear carbon chain products, such as 2-decanethiol,3-decanethiol, 4-decanethiol, 5-decanethiol, 3-dodecanethiol,5-dodecanethiol, 2-hexadecanethiol, 5-hexadecanethiol, and8-octadecanethiol, and the branched carbon chain products, such as2-methyl-4-tridecanethiol. Primary thiols are typically prepared fromterminal olefins by hydrosulfurization under free-radical conditions andinclude, for example, 1-butanethiol, 1-hexanethiol, 1-dodecanethiol,1-tetradecanethiol and 2-methyl-1-tridecanethiol.

Among the polyols, particular mention may be made of those having from 2to about 6 hydroxyl groups. Specific examples include the alkyleneglycols such as ethylene glycol, propylene glycol, hexylene glycol, anddecylene glycol, the polyalkylene glycol ethers, such as diethyleneglycol, triethylene glycol, propylene glycol, dipropylene glycol,tripropylene glycol, glycerine, sorbitol, and the like.

The alcohols (both mono- and poly-hydroxy) and the phenols (includingalkyl-substituted phenols) are preferred classes of active hydrogenreactants for purposes of the invention. Among the phenols, particularmention may be made of phenol and of alkyl-substituted phenols whereineach alkyl substituent has from one to about 30 (preferably from one toabout 20) carbon atoms, for example, p-methylphenol, p-ethylphenol,p-hexylphenol, nonylphenol, p-decylphenol, didecyl phenol and the like.

Acyclic aliphatic mono-hydric alcohols (alkanols) form a most preferredclass of reactants, particularly the primary alkanols, althoughsecondary and tertiary alkanols are also very suitably utilized in theprocess of the invention. Preference can also be expressed, for reasonof both process performance and commercial value of the product, foralkanols having from one to about 30 carbon atoms, with C₆ to C₂₄alkanols considered more preferred and C₈ to C₂₀ alkanols consideredmost preferred. As a general rule, the alkanols may be of branched orstraight chain structure, although preference further exists for alkanolreactants in which greater than about 50 percent, more preferablygreater than about 60 percent, and most preferably greater than about 70percent of the molecules are of linear (straight-chain) carbonstructure.

The general suitability of such alkanols as reactants in alkoxylationreactions is well recognized in the art. Commercially available mixturesof primary mono-hydric alkanols prepared via the oligomer tion ofethylene and the hydroformylation or oxidation and hydrolysis of theresulting higher olefins are particularly preferred. Examples ofcommercially available alkanol mixtures include the NEODOL Alcohols,trademark of and sold by Shell Chemical Company, including mixtures ofC₉, C₁₀ and C₁₁ alkanols (NEODOL 91 Alcohol), mixtures of C₁₂ and C₁₃alkanols (NEODOL 23 Alcohol), mixtures of C₁₂, C₁₃, C₁₄, and C₁₅alkanols (NEODOL 25 Alcohol), and mixtures of C₁₄ and C₁₅ alkanols(NEODOL 45 Alcohol); the ALFOL Alcohols, trademark of and sold by VistaChemical Company, including mixtures of C₁₀ and C₁₂ alkanols (ALFOL1012), mixtures of C₁₂ and C₁₄ alkanols (ALFOL 1214), mixtures of C₁₆and C₁₈ alkanols (ALFOL 1618), and mixtures of C₁₆, C₁₈ and C₂₀ alkanols(ALFOL 1620); the EPAL Alcohols, trademark of and sold by Ethyl ChemicalCompany, including mixtures of C₁₀ and C₁₂ alkanols (EPAL 1012),mixtures of C₁₂ and C₁₄ alkanols (EPAL 1214), and mixtures of C₁₄, C₁₆,and C₁₈ alkanols (EPAL 1418); and the TERGITOL-L Alcohols, trademark ofand sold by Union Carbide Corporation, including mixtures of C₁₂, C₁₃,C₁₄, and C₁₅ alkanols (TERGITOL-L 125). Also very suitable are thecommercially available alkanols prepared by the reduction of naturallyoccurring fatty esters, for example, the CO and TA products of Procterand Gamble Company and the TA alcohols of Ashland Oil Company.

Among the polyols, particular mention may be made of those having from 2to about 6 hydroxyl groups and 2 or more, preferably 2 to 30 carbonatoms. Specific examples include the alkylene glycols such as ethyleneglycol, propylene glycol, hexylene glycol, and decylene glycol, thepolyalkylene glycol ethers, such as diethylene glycol, triethyleneglycol, propylene glycol, dipropylene glycol, tripropylene glycol,glycerine, sorbitol, and the like. Higher oligomers and polymers of thepolyols are also very suitable.

The active hydrogen containing reactant is also very suitably thealkoxylate product of a previous alkoxylation of an active hydrogencontaining compound.

Further examples of both specific alkylene oxide reactants and specificactive hydrogen containing reactants suitable for use in this inventionare recited in the aforementioned U.S. Patents, the relevant disclosuresof which are incorporated herein by this reference.

The alkylene oxide reactant and the active hydrogen reactant arecontacted in the presence of a xerogel comprising one or more compoundsof a rare earth element and phosphorus. The rare earth/phosphorusxerogel catalysts of the present invention are dervied from hydrogelsand can be prepared by coprecipitation of a rare earth or lanthanidecompound, a phosphorus compound and a basic compound in an aqueoussolution.

In a preferred embodiment, the xerogels are prepared by coprecipitatingone or more rare earth or lanthanide compounds, a phosphorus compoundand a basic compound in an aqueous solution. Suitable lanthanidecompounds for use in the coprecipitation of the hydrogel includelanthanide chloride in the hydrated form, lanthanide nitrate andlanthanide carbonate, with lanthanide chloride in the hydrated formbeing preferred. Suitable phosphorus compounds include sodium phosphate,potassium phosphate and ammonium potassium phosphate, with sodiumphosphate being preferred. Suitable basic compounds include sodiumhydroxide, ammonium hydroxide, potassium hydroxide and cesium hydroxide.with sodium hydroxide being preferred. The precipitation is typicallycarried out at a temperature in the range of from about 5° C. to about95° C., preferably from about 20° C. to about 40° C. The length of timerequired for precipitation is typically from about 1 minute to about 1hour. The period of time for the precipitation should be sufficientlylong for adequate mixing of the materials so that a relatively stable pHis maintained.

After precipitation of rare earth/phosphorus-containing hydrogel, thehydrogel is subjected to stirring for at least about 30 minutes in orderto allow complete reaction to occur. Thereafter, the hydrogel isfiltered in routine fashion and washed to remove substantially all ofthe water-soluble salts formed during the precipitaion of the hydrogel.The preferred solvent for washing is water although other solvents suchas lower alkanols may be used.

The rare earth/phosphorus-containing hydrogel is then subjected todrying to form a xerogel. The extent to which water is removed from thehydrogel during drying will vary widely depending upon the solidscontent of the hydrogel and the nature of the drying operationconducted. Drying may be carried out using conventional means such asair drying, vacuum drying, forced draft drying or similar means. Dryingtemperatures are not critical and depend upon the particular meansutilized for drying and the extent to which drying of the hydrogel isdesired. Drying will typically be carried out at temperatures in therange of from about 80° C. to about 300° C. It is to be understood thatdrying of the hydrogel does not have to be complete and further dryingcan result in further removal of water.

In a preferred embodiment, the catalysts in the present inventioncontain from about 70 percent by weight to about 99 percent by weight,preferably from about 80 percent by weight to about 95 percent by weightsolids as determined by thermogravimetric analysis.

The rare earth/phosphorus xerogel catalysts thus prepared typicallycontain from about 40 percent by weight to about 75 percent by weight,preferably from about 50 percent by weight to about 70 percent byweight, basis total catalyst, of rare earth element, and from about 8percent by weight to about 15 percent by weight, preferably from about10 percent by weight to about 13 percent by weight, basis totalcatalyst, of phosphorus.

In addition, the catalyst may also suitably contain other substances,including those which may be introduced into the process as impuritiesas well as those which may be added to promote or modify catalystactivity.

The xerogel comprising one of more compounds comprising a rare earthelement and phosphorus is present in the reaction mixture in acatalytically effective amount, i.e., an amount sufficient to promotethe alkoxylation reaction or influence the alkoxylene oxide adductdistribution of the product. In a preferred embodiment, the catalyst isused in amount between about 0.1 percent by weight and about 10 percentby weight. preferably between about 0.5 percent by weight and about 3percent by weight, basis starting weight of active hydrogen reactant tobe ethoxylated. As a general rule, the higher the desired averagealkylene oxide adduct number of the product and the higher the desiredreaction rate, the greater the required quantity of catalyst.

In a preferred embodiment, the invention is a process which comprisescontacting and reacting an alkylene oxide reactant (particularly areactant comprising ethylene oxide, propylene oxide, or a mixture ofpropylene oxide and ethylene oxide) with an active hydrogen containingreactant (particularly an alcohol, polyol, or other hydroxyl containingcompound), in the presence of a xerogel comprising one or more compoundscomprising lanthanum and phosphorus wherein the catalyst contains fromabout 40 percent by weight to about 70 percent by weight, preferablyfrom about 50 percent by weight to about 65 percent by weight, basistotal catalyst, of lanthanum, and from about 8 percent by weight toabout 13 percent by weight phosphorus, preferably from about 10 percentby weight to about 12 percent by weight, basis total catalyst, ofphosphorus. In a most preferred embodiment, ethylene oxide is contactedwith a C₁ to C₃₀ primary alkanol in the presence of a xerogel comprisinglanthanum phosphate.

In terms of processing procedures, the alkoxylation reaction in theinvention may be conducted in a generally conventional manner. Theprocess can be carried out either batchwise or continuously, using afixed bed catalyst, or a stirrer equipped reactor or other mobilecatalyst contacting process as well as any other well known contactingtechnique. For example, the liquid active hydrogen reactant mayinitially be contacted with the catalyst. The catalyst and liquidreactant are contacted, preferably under agitation, with alkylene oxidereactant, which is typically introduced in gaseous form, at least forthe lower alkylene oxides. The order in which the reactants and catalystare contacted has not been found to be critical to the invention.

Overall, the two reactants are utilized in quantities which arepredetermined to yield an alkoxylate product of the desired mean oraverage adduct number. The average adduct number of the product is notcritical to this process. Such products commonly have an average adductnumber in the range from less than one to about 30 or greater.

In general terms, suitable and preferred process temperatures andpressures for purposes of this invention are the same as in conventionalalkoxylation reactions between the same reactants, employingconventional catalysts. A temperature of at least about 90° C.,particularly at least about 120° C. and most particularly at least about130° C., is typically preferred from the standpoint of the rate-ofreaction, while a temperature less than about 250° C., particularly lessthan about 210° C., and most particularly less than about 190° C., istypically desirable to minimize degradation of the product. As is knownin the art, the process temperature can be optimized for givenreactants, taking such factors into account.

Super-atmospheric pressures, e.g., pressures between about 10 and 150psig are preferred, with pressure being sufficient to maintain theactive hydrogen reactant substantially in the liquid state.

When the active hydrogen reactant is a liquid and the alkylene oxidereactant is a vapor, alkoxylation is then suitably conducted byintroducing alkylene oxide into a pressure reactor containing the liquidactive hydrogen reactant and the catalyst. For considerations of processsafety, the partial pressure of a lower alkylene oxide reactant ispreferably limited, for instance, to less than about 60 psia, and/or thereactant is preferably diluted with an inert gas such as nitrogen, forinstance, to a vapor phase concentration of about 50 percent or less.The reaction can, however, be safely accomplished at greater alkyleneoxide concentration, greater total pressure and greater partial pressureof alkylene oxide if suitable precautions, known to the art, are takento manage the risks of explosion. A total pressure of between about 40and 110 psig, with an alkylene oxide partial pressure between about 15and 60 psig, is particularly preferred, while a total pressure ofbetween about 50 and 90 psig with an alkylene oxide partial pressurebetween about 20 and 50 psig, is considered more preferred.

The time required to complete a process according to the invention isdependent both upon the degree of alkoxylation that is desired (i.e.,upon the average alkylene oxide adduct number of the product) as well asupon the rate of the alkoxylation reaction (which is, in turn dependentupon temperature, catalyst quantity and nature of the reactants). Atypical reaction time for preferred embodiments is in the range from 1to 24 hours.

After the ethoxylation reaction has been completed, the product ispreferably cooled. If desired, catalyst can be removed from the finalproduct, although catalyst removal is not necessary to the process ofthe instant invention. Any catalyst residues may be removed, forexample, by filtration, precipitation, extraction, or the like.

The ranges and limitations procided in the instant specification andclaims are those which are believed to particularly point out anddistinctly claim the instant invention. It is, however, understood thatother ranges and limitations that perform substantially the samefunction in substantially the same way to achieve the same orsubstantially the same result are intended to be within the scope of theinstant specification and claims.

The following Examples are provided to further illustrate certainspecific aspects of the invention but are not intended to limit itsbroader scope.

EXAMPLE 1

A lanthanum phosphate xerogel was prepared by the following procedure.Lanthanum chloride heptahydrate (15 grams, 40 mmoles) was dissolved in50 ml of deionized water, as were sodium hydroxide (3.2 grams.,80mmoles) in 50 ml of water and tribasic sodium phosphate dodecahydrate(5.07 grams, 16.7 mmoles) in 50 ml of deionized water. Deinonized water(350 ml) served as a heel for the precipitation. All three solutionswere added simultaneously in a dropwise fashion to the heel, maintaininga near neutral pH. The slurry was stirred at ambient temperature for 30minutes, filtered through a medium porosity frit, washed with 200 ml ofdeionized water, and partially dried on the frit by pulling air throughthe frit. The material was dried further at 120° C. under a rough (100mm) vacuum for several hours. The resulting material was 67% by weightlanthanum.

An alkoxylation process in accordance with the invention was conductedunder the following procedures. The alkylene oxide reactant for thisprocess embodiment consisted of ethylene oxide and the active hydrogen(20% branched), alkanols having twelve and thirteen carbon atoms (about40% by mol C₁₂ and 60% by mol C₁₃).

Initially, 2.0 grams of the powder prepared as described above was addedto 110 grams of NEODOL 23 Alcohol, and the mixture was heated in a 500milliliter autoclave to 140° C. under nitrogen sparge to drive offwater. A mixture of nitrogen and ethylene oxide was then introduced intothe reactor to a total pressure of 60 psia (30 psia nitrogen and 30 psiaethylene oxide). Alkoxylation (ethoxylation) commenced immediately.Additional ethylene oxide was supplied on demand to maintain anessentially constant 60 psia pressure. Temperature was maintained at140° C. A total of 161 grams of ethylene oxide was taken up over aperiod of 6 hours. The reactor was maintained for an additional 1 hourto consume unreacted ethylene oxide in the system.

The product was analyzed by GC-LC techniques and found to have a meanaverage adduct number of 5.8. The ethylene oxide adduct distribution ofthe product is presented in the following table. The only observedby-products were polyethylene glycols (PEG).

    ______________________________________                                        ETHOXYLATE DISTRIBUTION                                                       Adduct Number   Concentration                                                 ______________________________________                                        0               2.9% wt                                                       (Residual Alcohol)                                                            1               1.1                                                           2               1.8                                                           3               4.5                                                           4               9.4                                                           5               15.2                                                          6               17.8                                                          7               15.8                                                          8               11.5                                                          9               7.4                                                           10              4.5                                                           11              2.7                                                           12              1.7                                                           13              1.1                                                           14              0.7                                                           15              0.5                                                           ______________________________________                                    

EXAMPLE 2

A lanthanum phosphate xerogel was prepared by the following procedure.Lanthanum chloride heptahydrate (15 grams, 40 mmoles) was dissolved in50 ml of deionized water, as were sodium hydroxide (1.6 grams, 40mmoles) in 50 ml of water and tribasic sodium phosphate dodecahydrate(10.14 grams, 33.4 mmoles) in 50 ml of deionized water. Deinonized water(350 ml) served as a heel for the precipitation. All three solutionswere added simultaneously in a dropwise fashion to the heel, maintaininga near neutral pH. The slurry was stirred at ambient temperature for 30minutes, filtered through a medium porosity frit, washed with 200 ml ofdeionized water, and partially dried on the frit by pulling air throughthe frit. The material was dried further at 120° C. under a rough (100mm) vacuum for several hours. The resulting material was 63% by weightlanthanum.

Two grams of this powder was added to 110 grams of the NEODOL 23 Alcoholin a 500 milliliter autoclave, and the temperature of the mixture wasramped to 140° C. under nitrogen sparge to drive off water. The alcoholwas ethoxylated at 140° C. and at a pressure of 60 psia (30 psiaethylene oxide and 30 psia nitrogen). A total of 202 grams of ethyleneoxide was consumed over a period of 2.5 hours, yielding a product havinga mean average adduct number of 7.8. The adduct distribution of thisproduct is presented in the following table.

    ______________________________________                                        ETHOXYLATE DISTRIBUTION                                                       Adduct Number   Concentration                                                 ______________________________________                                        0               1.2% wt                                                       (Residual Alcohol)                                                            1               0.5                                                           2               0.5                                                           3               0.5                                                           4               2.0                                                           5               7.7                                                           6               17.5                                                          7               22.9                                                          8               18.8                                                          9               11.5                                                          10              6.2                                                           11              3.4                                                           12              2.1                                                           13              1.5                                                           14              1.0                                                           15              0.8                                                           ______________________________________                                    

EXAMPLE 3

A lanthanum phosphate xerogel was prepared by the following procedure.Lanthanum chloride heptahydrate (15 grams, 40 mmoles) was dissolved in50 ml of deionized water, as was tribasic sodium phosphate dodecahydrate(15.2 grams, 40 mmoles) in 50 ml of deionized water. Deinonized water(350 ml) served as a heel for the precipitation. Both solutions wereadded simultaneously in a dropwise fashion to the heel, maintaining anear neutral pH. The slurry was stirred at ambient temperature for 30minutes, filtered through a medium porosity frit, washed with 200 ml ofdeionized water, and partially dried on the frit by pulling air throughthe frit. The material was dried further at 120° C. under a rough (100mm) vacuum for several hours. The resulting material was 58% by weightlanthanum.

Two grams of this powder was added to 110 grams of NEODOL 23 Alcohol. Anethoxylation reaction was then carried out according to the proceduresdescribed in Example 2. A total of 200 grams of ethylene oxide wasconsumed over a 2.5 hour period at a reaction temperature of 140° C. Theproduct had a mean average adduct number of 6.5. The adduct distributionof this product is presented in the following table.

    ______________________________________                                        ETHOXYLATE DISTRIBUTION                                                       Adduct Number   Concentration                                                 ______________________________________                                        0               2.3% wt                                                       (Residual Alcohol)                                                            1               0.8                                                           2               0.7                                                           3               1.5                                                           4               4.3                                                           5               11.3                                                          6               19.2                                                          7               20.8                                                          8               15.5                                                          9               9.3                                                           10              5.2                                                           11              2.9                                                           12              1.8                                                           13              1.2                                                           14              0.8                                                           15              0.7                                                           ______________________________________                                    

What is claimed is:
 1. A process for the preparation of alkylene oxideadducts of active hydrogen containing organic compounds, which comprisescontacting and reacting an alkylene oxide reactant comprising one ormore vicinal alkylene oxides with an active hydrogen containing reactantcomprising one or more active hydrogen containing organic compounds, inthe presence of a catalytically effective amount of a xerogel comprisinga rare earth phosphate.
 2. The process of claim 1 wherein said rareearth phosphate is selected from the group consisting of lanthanumphosphate, cerium phosphate, neodymium phosphate, samarium phosphate,gadolinium phosphate, dysprosium phosphate and mixtures thereof.
 3. Theprocess of claim 1 wherein said rare earth phosphate is lanthanumphosphate.
 4. The process of claim 1 wherein said xerogel contains fromabout 40 percent by weight to about 75 percent by weight rare earthelement and from about 8 percent by weight to about 15 percent by weightphosphorus.
 5. The process of claim 4 wherein said xerogel contains fromabout 50 percent by weight to about 70 percent by weight rare earthelement and from about 10 percent by weight to about 13 percent byweight phosphorus.
 6. The process of claim 1 wherein said xerogelcomprises about 70 percent by weight to about 99 percent by weightsolids.
 7. The process of claim 6 wherein said xerogel comprises about80 percent by weight to about 95 percent by weight solids.
 8. Theprocess of claim 1 wherein the alkylene oxide reactant comprises one ormore alkylene oxides selected from the group consisting of ethyleneoxide and propylene oxide.
 9. The process of claim 8 wherein the activehydrogen containing reactant comprises one or more compounds selectedfrom the group consisting of alkanols, phenols and polyols.
 10. Theprocess of claim 9 wherein the active hydrogen containing reactantcomprises one or more active hydrogen containing compounds selected fromthe group consisting of alkanols having from one to about 30 carbonatoms and alkyl-substituted phenols wherein each alkyl substituent hasfrom one to about 30 carbon atoms.
 11. The process of claim 10 whereinthe active hydrogen containing reactant comprises one or more C₁ -C₃₀primary mono-hydric alkanols.
 12. The process of claim 11 wherein theactive hydrogen containing reactant comprises primary mono-hydricalkanols having carbon numbers in the range from 6 to 24, inclusive, andthe alkylene oxide reactant comprises ethylene oxide.
 13. The process ofclaim 12 wherein the active hydrogen containing reactant comprisesprimary mono-hydric alkanols having carbon numbers in the range from 8to 20, inclusive.
 14. The process of claim 13 wherein greater than about50% of the molecules of the primary mono-hydric alkanols are of linearcarbon structure.
 15. The process of claim 14 wherein greater than about70% of the molecules are of linear carbon structure.
 16. A process forthe preparation of alkylene oxide adducts of active hydrogen containingorganic compounds, which comprises contacting and reacting an alkyleneoxide selected from the group consisting of ethylene oxide and propyleneoxide, with an active hydrogen containing reactant selected form thegroup consisting of alkanols, phenols and polyols, in the presence of acatalytically effective amount of a xerogel comprising lanthanumphosphate.
 17. The process of claim 16 wherein said xerogel containsfrom about 40 percent by weight to about 70 percent by weight lanthanumand from about 8 percent by weight to about 13 percent by weightphosphorus.
 18. The process of claim 17 wherein said xerogel containsfrom about 50 percent by weight to about 65 percent by weight lanthanumand from about 10 percent by weight to about 12 percent by weightphosphorus.
 19. The process of claim 16 wherein said xerogel comprisesabout 70 percent by weight to about 99 percent by weight solids.
 20. Theprocess of claim 19 wherein said xerogel comprises about 80 percent byweight to about 95 percent by weight solids.
 21. The process of claim 16wherein the active hydrogen containing reactant comprises one or moreactive hydrogen containing compounds selected from the group consistingof alkanols having from one to about 30 carbon atoms andalkyl-substituted phenols wherein each alkyl substituent has from one toabout 30 carbon atoms.
 22. The process of claim 21 wherein the activehydrogen containing reactant comprises one or more C₁ -C₃₀ primarymono-hydric alkanols.
 23. The process of claim 22 wherein the activehydrogen containing reactant comprises primary mono-hydric alkanolshaving carbon numbers in the range from 6 to 24, inclusive, and thealkylene oxide reactant comprises ethylene oxide.
 24. The process ofclaim 23 wherein the active hydrogen containing reactant comprisesprimary mono-hydric alkanols having carbon numbers in the range from 8to 20, inclusive.
 25. The process of claim 24 wherein greater than about50% of the molecules of the primary mono-hydric alkanols are of linearcarbon structure.
 26. The process of claim 25 wherein greater than about70% of the molecules are of linear carbon structure.